After Panama pit stop, Navy stealth ship steams toward San Diego

No longer waylaid by mechanical glitches, the Navy’s newest and most expensive destroyer is sailing to San Diego.

Slated to arrive here within the next two weeks, the $4 billion guided-missile destroyer Zumwalt lost propulsion while transiting the Panama Canal on Nov. 21, clanged into the side of the channel and needed a tow for emergency repairs on the western side of the Central American country.

The Zumwalt left the mammoth MEC Shipyards Balboa complex Wednesday evening after crew members and teams from Naval Sea Systems Command and General Electric mended the sleek and stealthy warship’s lube oil coolers, according to the Navy.

Those were the same coolers that failed in late September off the coast of Virginia, but the Navy believes technicians have pinpointed the gremlins and the mishap caused no permanent damage to the vessel.

“The technical community is working with the equipment manufacturers to determine why the failures occurred and to prevent recurrences,” Cmdr. Clay Doss, spokesman for the U.S. Pacific Fleet, said in a statement to The San Diego Union-Tribune. “At this point, it is unclear if the problems were caused by a design flaw. In addition to reviewing the design, the technical community is looking at ways to operate the lube oil coolers more effectively.”

Capable of slicing through waves like a switchblade and sculpted to sneak past enemy radar, the Zumwalt is the first in its class of experimental warships built to radically reshape how the Navy battles for control of the seas.

With enough power to drive 10 traditional destroyers, General Electric’s high-tech electrical system veins the Zumwalt, sending energy to advanced sensors and future weapons like electromagnetic pulse cannons that have yet to be perfected.

The system also connects to the induction motors that make the Zumwalt’s port and starboard propeller shafts work.

When sailors on Nov. 21 began probing the mysterious drop in the Zumwalt’s propulsion, they found water leaking into one of the induction motor’s bearing sump, according to Doss.

To the sailors, that “meant that the lube oil cooler for that bearing was leaking,” Doss wrote.

The ship’s four bearings and their sumps are part of a crucial lubrication and cooling system that keeps the Zumwalt’s parts from grinding together or burning up -- much like oil smoothly slides through a car engine to coat metal pieces and make the motor hum.

Doss promised that the Zumwalt’s crew will constantly monitor the bearings as the destroyer continues its westward journey to San Diego.

Before arriving in the canal, the Zumwalt visited the Navy’s Mayport station in Florida and then sailed to Cartagena, Colombia.

The warship is scheduled to undergo testing, training and continued innovation in San Diego, making it ready for combat deployments in about a year, the Navy estimates.

Originally planned for a production run of 32 ships but dogged by rising costs, the Pentagon has slashed the nearly $23 billion Zumwalt-class program to only three vessels.

The second ship in its class, the Michael Monsoor, should become fully operational in 2018, and the Lyndon B. Johnson will reach the same milestone three years later, the Navy had said.